Various dental floss holders have previously been described wherein a length of dental floss is held under tension. For instance, in U.S. Pat. Nos. 4,736,757, 4,427,018, 2,444,697, and 1,815,408 opposing resilient arms are arranged such that the arms are moved toward one another when the floss is inserted. Subsequent to inserting the floss, the arms are released. Due to the resiliency of the arms, the arms tend to move apart from one another to their original position, thereby initially tensioning the floss.
Another device disclosed in U.S. Pat. No. 1,217,779 is adapted to hold floss under tension by using a retaining bar which spaces two opposed floss holding arms. The opposing arms have slits at their ends to receive the floss and the arms taper at the floss holding ends. Movement of the retaining bar toward the tips allows the arms to be compressed, providing relative movement toward one another. A length of floss is then inserted through the slits. By moving the bar away from the end, the arms move apart, thus resulting in the tensioning of the length of floss therebetween.
Each of the above described devices, however, has a similar drawback. The drawback relates to the stretching of floss during use. As the floss stretches, the devices are not capable of providing further tensioning of the floss beyond the normal original position of the arms.
One device, disclosed in U.S. Pat. No. 3,910,294, enables a continuous adjustment of the floss tension, but does so at the expense of a complex series of axes and the manual adjustment of a "tension adjusting lever." Adjustment of the lever pulls on the floss to create greater tension. Therefore, a second hand may be required by the operator to adjust the tension.
Therefore, there exists a need to develop a simple dental floss device which is capable of providing a continuous tensioning force to a length of floss as the length of floss stretches during use.